Debt and Financing Arrangements (Tables)

6 Months Ended

Oct. 31, 2012

Debt and Financing Arrangements [Abstract]

Long-term debt

		October 31, 2012	April 30, 2012
4.78%	Senior Notes due June 1, 2014	100,000	100,000
6.12%	Senior Notes due November 1, 2015	24,000	24,000
6.63%	Senior Notes due November 1, 2018	396,486	397,906
3.50%	Notes due October 15, 2021	748,710	748,637
5.55%	Senior Notes due April 1, 2022	400,000	400,000
4.50%	Senior Notes due June 1, 2025	400,000	400,000
Total long-term debt		2,069,196	2,070,543
Current portion of long-term debt		50,000	50,000
Total long-term debt, less current portion		2,019,196	2,020,543